Mitsubishi Electric MELSEC-A/QnA Series Handbook page 6

[Wiring Precautions]
● Shut off the external power supply (all phases) used in the system before wiring.
Failure to do so may result in electric shock or damage to the product.
● After wiring, attach the included terminal cover to the module before turning it on for operation.
Failure to do so may result in electric shock.
● Individually ground the FG and LG terminals of the programmable controller with a ground
resistance of 100 or less.
Failure to do so may result in electric shock or malfunction.
● Use applicable solderless terminals and tighten them within the specified torque range.
If any spade solderless terminal is used, it may be disconnected when the terminal screw comes
loose, resulting in failure.
● Check the rated voltage and terminal layout before wiring to the module, and connect the cables
correctly.
Connecting a power supply with a different voltage rating or incorrect wiring may cause a fire or
failure.
● Connectors for external devices must be crimped or pressed with the tool specified by the
manufacturer, or must be correctly soldered.
Incomplete connections may cause short circuit, fire, or malfunction.
● Tighten the terminal screws within the specified torque range.
Undertightening can cause short circuit, fire, or malfunction.
Overtightening can damage the screw and/or module, resulting in drop, short circuit, or malfunction.
● Prevent foreign matter such as dust or wire chips from entering the module.
Such foreign matter can cause a fire, failure, or malfunction.
● A protective film is attached to the top of the module to prevent foreign matter, such as wire chips,
from entering the module during wiring.
Do not remove the film during wiring.
Remove it for heat dissipation before system operation.
● Mitsubishi programmable controllers must be installed in control panels.
Connect the main power supply to the power supply module in the control panel through a relay
terminal block.
Wiring and replacement of a power supply module must be performed by qualified maintenance
personnel with knowledge of protection against electric shock.
For wiring methods, refer to the QCPU User's Manual (Hardware Design, Maintenance and
Inspection).
A
- 4
WARNING
CAUTION